Work machines are often equipped with a work machine arm capable of performing any number of tasks. For example, a work machine such as a backhoe or an excavator may include a digging work machine arm. Likewise, a work machine such as a forklift or a telescopic material handler may include a work machine arm for lifting and carrying objects. Other work machines may include work machine arms that are adapted to support vibratory compactors or other equipment.
Because controlling a work machine arm is often a complex process, an inexperienced operator may have difficulty moving an element of the work machine arm, such as a work implement, along a desired path. To simplify the coordination required to accomplish this, some work machines are provided with a single input device that controls the movement of all the components of the work machine arm. Use of a single input device may simplify the operation of the work machine arm and reduce operator fatigue.
U.S. Pat. No. 6,374,153 to Brandt et al. discloses an apparatus and method for providing coordinated control to a telescopic material handler. Often, a material handler is used to raise a pallet in a vertical direction. The coordinating apparatus of the '153 patent enables an operator to more easily control the material handler arm so that it moves along the vertical path by simultaneously changing both the length and the angle of the boom. The '153 patent discloses a control system that calculates a compensating error that may develop when one hydraulic cylinder does not receive the necessary hydraulic fluid flow due to the demand of flow from another cylinder.
At times, it may be desirable to move different components of the work machine arm in an order of priority that can be adapted to the needs of a specific work site. For example, when a work machine arm is used to dig in an area adjacent a standing structure, a bucket on the work machine arm must be extended so that the bucket edge approaches the wall before the back of the bucket. In another example, the life of a specific, expensive component of the work machine arm may be prolonged by using it only when necessary. Current work machines having systems for coordinated movement do not provide for prioritizing the movement of different components of the work machine arm.
The present invention is directed to overcoming one or more of the disadvantages of the prior art.